Manufacture of shoes



1933. R. A. LINEHAM MANUFACTURE OF SHOES Filed Feb. 24. 1932 Fig.1.

e a? vmmm Patented Dec. 5, 1933 UNITED STATES MANUFACTURE OF SHOES Rowland Augustus Lineham, Leicester, England,

asslgnor to United Shoe Machinery Corporation, Paterson, N. 5.,

Jersey a corporation of New Application February 24, 1932, Serial No. 594,850, and in Great Britain March 13, 1931 8 Claims.

This invention relates to the manufacture of shoes. The invention is herein shown and described by way of illustration in its application to welts and welt shoes in which the outer or wearing sole is secured to a ribbed insole and an upper by means of a. welt, with special reference to its applicability to the waterproofing or sealing of the inseams of such shoes although the invention is not limited to use in the manufacture of shoes of the type referred to, or to shoes having sealed inseams. Ordinarily such inseams are formed by stitches formed from waxed thread and passing through holes extending through the between-substance at the base of the rib on the insole, through the upper and through the welt.

Furthermore, the present invention, in certain respects, may be considered as in the nature of an improvement on the invention set forth in an application for United States Letters Patent Serial No. 580,794, filed December 14, 1931, in the name of Arthur Bates.

In important aspects the present invention provides an improved welt especially adapted for use in producing shoes with sealed inseams, an improved shoe having a sealed inseam and a method of making shoes in which such a welt may advantageously be employed.

As disclosed in the Bates application abovementioned and in accordance with the preferred manner of practising the present invention, the welt before it is secured to the upper and insole is provided, on that face which is to lie next to the upper, with a material which becomes effective, during the operation of attaching the welt, to seal the holes which are made in the parts which are thus fastened together. Preferably this material is non-plastic at normal room temperatures but may be rendered plastic by heat and may be. somewhat flexible and non-brittle when cold.

As set forth and claimed in said prior application, Bates proposed to apply such a thermoplastic material, in the form of a coating or surface deposit, to the welt before it is assembled in the shoe and then to heat said material just before or as it is being applied to the upper so that said material will be forced into the holes of the inseam by the inseaming operation.

One object of the present invention is to secure so a still more effective sealing of a seam and, to

that end, the present invention, in one aspect,

provides a welt having a formation such that,

during the attaching of the welt, the sealing material'is confined to the attaching region and a 55 minimum amount of said material is squeezed out laterally of the inseam, with the result that a maximum amount of the material is forced into the holes of the inseam. In a preferred embodiment, the welt of the present invention has formed in that face thereof which is to lie next to the upper a groove preferably in the region through which the holes are to be formed in the welt and a thermoplastic material is laid in this groove before the welt is assembled with the upper. Preferably also, the usual sewing groove is provided upon that face of the welt which is to lie next to the outsole.

In making a welt shoe according to a preferred mode of practising the method of the present invention, such a welt is sewn to the upper and to the insole by an inseam which may be formed in any usual or suitable way, as by the well-known Goodyear welt sewing machine, the stitches of the inseam preferably passing through the two grooves in the welt. As each stitch of the inseam is tightened and set, the thermoplastic material in the groove, which has been rendered plastic by heat, will be forced, by the drawing of the welt against the upper, to flow into the holes and about the stitches of the inseam to seal the inseam. The corners formed at the face of the welt by the groove therein will prevent the escape to any substantial extent of the plastic material laterally of the inseam.

The above and other objects and characteristics of the invention will become more clearly apparent from the following detailed description with reference to the accompanying drawing of a preferred form of welt and illustrating a preferred method of employing it, according to the present invention, in the production of a shoe.

In the drawing,

Fig. l is a magnified cross section of a welt made according to the present invention, and

Fig. 2 shows in section and more or less diagrammatically the inseam portion of a welt shoe after the welt has been attached and the inseam has been sealed.

In carrying the present invention into effect, the welting employed may be either in a continuous 10o length or in separate pieces each long enough to make the welt for one shoe. Such welting is indicated at 10 with a groove 12 and a corner bevel 14 at that face of the welt which will be lowermost in the shoe when it is being worn. In addition, the opposite face, which is to be uppermost in the shoe when it is being worn, is provided with a groove 16 preferably so located with relation to the inner edge of the welt that the inseam will pass through both grooves 12, 16. This groove 1.10

16 is shown as substantially semi-circular in section with two sharp corners 18, 20, but various other shapes are suitable. In this groove 16 is laid thermoplastic material 22 which may merely fill the groove level with the face of the welt or which may project outwardly as a bead beyond said face, as shown in Fig. 1. This thermoplastic material may be applied with a hand tool or brush but, more conveniently, may be applied by passing the welt through a coating device which may embody a small tank containing the molten thermoplastic material which is lifted by a. wheel for applying a band to the welt, this latter being directed by lateral guides, so that the band fills the groove 16 and may extend laterally along the welt face a limited distance and may project outwardly beyond that face as already stated.

The act of fastening such a welt to a shoe by a welt sewing machine, such as the Goodyear welt sewing machine above referred to, produces a result similar to that illustrated in Fig. 2 in which is shown the upper material 24 of a shoe with its lining, an insole 26 with its rib or lip 28 and a waxed thread forming the stitches 30 of the inseam. A principal effect of the pulling together tightly of the welt, upper and insole lip during this sewing operation is to bend the marginal portion of the face of the welt outside of the corner 20 toward the opposite face of the welt in which is the groove 12 and the curved contour of the groove 16 is flattened out while the corners l8 and 20 are pressed firmly into contact with the shoe upper 24. Hence, these corners effectively prevent the material 22 from escaping laterally in any considerable quantity from between those areas of the welt and upper which are drawn by the sewing against one another and that material is therefore largely forced, by the flattening out of the contour of the groove 16, into the holes through the work made by the needle in sewing the seam, besides forming a seal along the inseam. The material is thus forced to flow about the stitches 30 and to fill the holes for a considerable portion of their length, as indicated at 32.

Although the surface of the welt between the corners 18, 20 is indicated in Fig. 2 as slightly concavely curved, this surface, in fact, especially when the welt is attached by thread strongly tensioned, may be entirely flattened out against the upper or even forced to a slightly convex curvature if the portion of the upper against which it is drawn has a concave curvature. Moreover,

' the use of such a band that is plastic or only semifiuid when the welt attaching operation is performed may ensure by mere presence of the thermoplastic material in quantity beyond that which is forced into the stitch holes that some of this material will be left as a continuous band of sealing material extending all along the inseam between the welt and upper from stitch hole to stitch hole and to some extent laterally thereof as shown at 34, the surface of the welt between the corners 18, 20 remaining concave to some degree, as indicated in Fig. 2.

Such a welt may be sewn to a shoe by the usual commercial welt sewing machines which, as described in the Bates application above referred to, may be provided with means for causing the thermoplastic material to become plastic or tacky by heat applied at one small locality progressively along the length of the welt as the sewing progresses. However, the invention, in its broader aspects, may be carried out by attaching the welt to the shoe while the thermoplastic material is cold and applying heat thereto at some later stage in its manufacture to cause the thermoplastic material to become plastic and to seal the inseam.

Furthermore, the attachment of the welt may be by an operation otherwise than by sewing, for example, by stapling inwhioh case the provision of a band of sealing material between the welt and the upper serves to render waterproof the line of the seam which has less continuity generally than that of a sewn seam.

In employing a thermoplastic band, as indicated above, it may be convenient to use a wax or sealing material which is at least compatible with any wax employed in finishing the welt and sole edge surfaces of the shoe and also to use Wax of the same color as that intended to be used for such finishing operations, since in such case any of the material which may be visible on the welt surface beyond the actual angle of the crease, after the welt has been attached to the shoe, will, if on any heating of the shoe (bottom down) it does not sink into and disappear in the crease, then amalgamate with the wax employed in the subsequent finishing operations. 7

A thermoplastic material which has been found to have desirable qualities for the purposes of the invention, in that it does not require an undue degree of heat to become sufficiently tacky, is not brittle when cold and has good adherence gener- V ally to finished leather surfaces such as those of uppers and the surfaces of welts, is one containing a large proportion of asphalt and a small proportion of resin; for instance:--60 parts (by weight) of air blown asphalt, 10 parts of Chatter- 1 ton's compound", and 30 parts of resin (0010- phony). V

"Chattertons compound" is a well-known insulating substance made of guttapercha, resin and tar.

Having thus indicated the nature and scope of the invention and having described in detail one way in which it may be carried out, what I claim is:

l. A method of making a welt shoe, which includes a ribbed insole, an upper and a welt, which method comprises forming a groove in each of the opposite faces of a welt and laying in that groove which is to lie next to the shoe upper a normally non-plastic material which may be rendered plastic by heat, assembling the welt with a ribbed insole and an upper, heating said material, forming holes through the welt in the region of both grooves and through the upper and the insole, uniting said parts by an inseam having stitches passing through said holes, drawing said parts tightly together and thereby causing said material while plastic to flow about the stitches to seal the inseam.

2. A method of making a welt shoe, which includes a ribbed insole, an upper and a welt, which 35 method comprises forming a groove in that face of the welt which is to lie next to the shoe upper, laying in that groove a thermoplastic material, assembling the welt with an insole and an upper, heating said material, sewing the parts together by an inseam, and simultaneously causing said material to flow about the stitches to seal the inseam.

3. A method of making a shoe which comprises 5 forming a groove in that face of a welt which is to lie'next to the shoe upper, providing sealing material in said groove and securing the welt to other parts of the shoe by a seam passing through the welt and said other parts, and simultaneously 150 causing said material to flow about the securing means to seal the seam.

4. A shoe having, in combination, a ribbed insole, an upper and a welt, the latter having grooves in its opposite faces and said parts being held together by an inseam passing through holes formed in said parts and through both grooves in the welt, and a thermoplastic material surrounding the stitches of the inseam in said holes and extending longitudinally therefrom along the inseam and sealing the inseam.

5. A shoe having, in combination, a ribbed insole, an upper and a welt having a groove in that face which lies next to the upper, said parts being held together by an inseam and a thermoplastic material lying in the groove and extending into and sealing the inseam.

6. A welt having in that face which is to contact with the shoe upper a groove and a thermoplastic sealing material filling the groove and extending outwardly beyond said face.

'7. For the production of shoes having sealed inseams, a welt having in that face which is to contact with the shoe upper a groove and an inseam sealing material therein.

8. For the production of welt shoes having sealed inseams, a welt having a groove in that face which is to contact with the shoe upper such that sealing material applied to its attaching region is substantially confined within that region by the act of attaching the welt to a shoe.

ROWLAND AUGUSTUS LINEHAM. 

